On Thu, Sep 11, 2008 at 02:35:22PM -0700, Yushu Yao wrote: If you're using virtio or PV drivers, then the speed of the virtual network interface is essentially limited by the speed of communication between host and guest kernels. Usually some form of ring of shared memory buffers is used. No other communication method can possibly be any faster, so then you'd be looking at whether the network protocol itself (ie. NFS) was itself efficient, and NFS has gone through enough inspection and tuning that it's hard to see that you could do better with a custom protocol written from scratch. So I would conclude: (1) Install virtio or PV drivers. (2) Stick with a network file sharing protocol that you're familiar with. (3) Test both the speed of the virtual network interface and the file sharing protocol. (4) Use standard methods to tune both until you reach an acceptable speed. Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into Xen guests. http://et.redhat.com/~rjones/virt-p2v